Seed dormancy

 Seed dormancy is a state of seed that make unable to seed germination, even if sufficient condition of germination is present.

Seed dormancy may be in different cotagories.

On the basis of dormancy based on inside factor and outside factor is endogenious dormancy and exogenious dormancy. 

When seed become dormant for outaide environment of seed is exogenious dormancy. When seed dormant based internal factors of seed called endogenious seed dormancy.

The different factor that plays a vital role in seed to become dormant is as bellow,

The immaturity of seed

Temperature of environment

Water Insufficiency

The existence of chemical prohibitors

Seed coat structure

Light

There should have three kinds of dormant seed and seed dormancy.

Innate dormancy

Innate dormancy of seed that seed become dormant even existing the favorable environment to germinate. If the fruit is immatured seed could be dormant. It is the primary dormancy.

Enforced dormancy： If seed is matured to germinate but show dormancy for external environmental forces is called enforced dormancy.

Induced dormancy： When any matured seed places under any unfavorable environment for a short period of time but when it found anyy favorable environment it may shows dormancy. That is induced dormancy.

A dormant seed may be capable to germinate if sufficient level of environment is provided. Even some mechanical and chemical expousere may break down dormancy. Breakdown of seed dormancy is beneficial for cultivators because it can prevent loss.

A one thing should taken into consideration that immature seed in plant fruit will breakdown its dormancy when it matured in plant.

How breakdown of seed dormancy will occur depends on the causes of dormant seed. 

If seed dormancy is caused for thick seed coated then dormancy may be break down by thining of coats by mechanical or chemical exposure.

If temperature impacts on seed dormancy then the changing of temperature may breakdown the dormancy.

If embryo of seed be sufficient level of matured its dormancy is easier to breakdown. 

Water infiltration is very important for seed to germinate. Hence, wet environment is very essential for germination. 

Wetting of seed allows the seed to expand in size. It also allows infiltration of water. 

Types of plants

 Plants are categorized into three class. Based on growth behaviour plants are categorized into herbs, shrubs and trees.

Herbs

Herbs are smallest greeny plant.  It have no woody tissue. All kinds of grasses, banana plants are the examples of herbs. Herbs contains vitamins and minerals a lot of. 

Shrubs

Shrubs are longer than the herbs but smaller than trees. Shrubs are woody but not harder like trees. Rose plants, lemon plants are the examples of shrubs.

Trees are longest plant and woody structure. Climbers and creepers are also considered as trees. 

Cell division

 The process by which a cell is divided is called cell division. Cell growth occurs through cell division. From unicellular organism to multi cellular organisms growth and reproduction through cell division.

Prokaryotic cell divide through a process called amitosis cell division which is also called binary fission.

Different types of bacteria and amoeba shows amitosis cell division.

Multi cellular animals shows mitosis cell division.

The reproductive cell divide through miosis cell division.

Inheritence

 Inheritence means property received by successor from ancestor. 

Animals and plants even any living organism received property from ancestor is called inheritence. 

Ancestors behaviour, physical characteristics, like color, height, and appearance transfers to successor. 

inherritence is the parts of Genetics that explains the property transfer from ancestors to successor.

Prokaryotic cell

 The cell that have non structured nucleus is called prokaryotic cell. Prokaryotic cell also missed other essential organallie. 

In eukaryotic cell there have structured nucleus. 

In prokaryotic cell nucleus the nuclear membrane is not exist. In terms of cell division prokaryotic cell is different from eukaryotic cell. Horizontal cell division occurs by binary fission of prokaryotic cell. This is Amitosis cell division.

Bacteria and Amoeba is unicellular organism. These are the examples of prokaryotic cell.

Eukaryotic cell divide with mitosis cell division. Specialized cell egg cell and sperm cell divide with miosis cell division.

Calvin cycle

 Calvin cycle is a dark reaction cycle of photosynthesis. It is a carbon reduction cycle of photosynthesis. Glucose is produces in calvin cycle by converting carbon di oxide into glucose and simaltaneously carbon is reduced in this cycle.

NADPH is an essential element in calvin cycle that is short lived and produces from light dependent reaction. Hence, Calvin cycle can not completely a dark reaction phase.

Chloroplast

 Chloroplast is a pigmented organalae that found in plant cell. The green color of plant is depends on chloroplast. 

It is a one kind of plastid in plant cell that is responsible for green color. 

Example is chlorophile. Plant leaf produces energy by photosynthesis with the use of chlorophyl.

Chloroplast is very important element in oxygenic photosynthesis and metabolism process.

It is also a regulator of plant response in abiotic and biotic stress condition of plant.

Chloroplast also consists different types of phytohormones and metabolites. The own genome and gene expression machinary introduced unique characteristics of chloroplast.

It produces NADPH by a process called photolysis

It produces ATP, Adenosine tri phosphate by photosynthesis.

Carbon di oxide have to absorb by plant that happes during Kelvin cycle. Kelvin cycle is also called the dark reaction of photosynthesis.